Thursday, September 07, 2017
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Sabine Hossenfelder drew a banner with the "interpretation of quantum mechanics"

that was supposed to be in a text but it was later removed. I consider her a fake physicist which was fabricated by the affirmative action – at least if you talk about anything she's been doing since the grad school – but I think that she has learned some undergraduate physics in a better way than at least 90% of the people who write about physics for the public.

The chart and most of the things she says about it are largely reasonable, except for a few things. Two of them are fundamental: she is treating the Copenhagen Interpretation in an atrocious way and she doesn't really explain that and why all other "interpretations" are nonsense.

One thing she says elsewhere is that "QBism", as she defined it, is the common denominator of all "interpretations". She – she means "the observer" – updates her knowledge about things, and updates the wave function that summarizes all the knowledge, when she makes an observation. So the collapse of the wave function is an unavoidable and inseparable description of the updated knowledge. The collapse and the updated knowledge are the same thing. She doesn't write these things this crisply but I suspect she would agree.

Yes, this is quantum mechanics, this is the only correct description of what's going on during the measurement, and this description has been called QBism. However, what she obfuscates is that the same principle is what has been called the Copenhagen Interpretation, too. That's what Heisenberg and Bohr – and perhaps a few pals – discovered and what they should be absolutely worshiped for. It's disgusting for her and others to place the "Copenhagen Interpretation" at the last place and describe it as

I don't care if the cat is dead

which looks like a joke or an expression of some moral indifference or relativism and has obviously nothing whatever to do with the Copenhagen Interpretation. The fact that during the measurement, the observer needs to update his knowledge, it mathematically corresponds to a discontinuous change of the wave function etc., and the perturbation caused by any observation is unavoidable, is what Heisenberg invented for the first time, what he summarized in his Nobel prize lecture in 1932, and what he really got his Nobel prize for. And the discovery was profound, as proven by the fact that lots of people are completely incapable of even understanding it (let alone discovering it) as much as 92 years after the discovery.

It was a core discovery that turned him into one of the most essential people of the history of physics in the 20th century and whoever doesn't understand this point doesn't understand the history of modern physics at all.

I have learned these things as a teenager from the original sources, from texts by Dirac, Pauli, Heisenberg, Bohr, and others. I still remember the vivid description of discussions between the founding fathers of quantum mechanics who said that the collapse of the wave function is analogous to the shrinking of the region where your friend may be – after you learn that he was seen at the London Airport a few minutes ago. It's just ludicrous for some clowns to claim that they're the discoverers of these things just because they give it a new label, QBism, and after they demagogically erase some crosses from the labels, just like Lidl did.

Aside from this disservice she does to the Copenhagen Interpretation and the failure to understand that QBism is nothing else than an effort to steal the credit for the Copenhagen Interpretation, her slogans that summarize the other "interpretations" are OK enough. This list is a politically correct way to describe the sociology of this community – what sort of stuff has been said about quantum mechanics.

All the other "interpretations" are nothing else than alternative classical theories that try to emulate quantum mechanics (i.e. the Copenhagen Interpretation) by adding one kind of classical variables and/or processes or another. The sketches of what they're trying to do are OK even though a more detailed description is needed to understand. But if someone is presenting not only sociology but also physics, he should explain why all these "classical models" that try to build something "beyond the common denominator" are fatally flawed and inconsistent with the totality of observations of Nature that the people have made.

This crucial part of the explanations of physics is being omitted for reasons that may be classified as another example of the political correctness. They have been labeled "negative" and that's why one isn't "allowed" to talk about them. It is politically incorrect to point out something that implies that Sean Carroll and all these individuals are crackpots, guys who are absolutely clueless about the inner logic of quantum mechanics. He has and they have screamed that there is a problem (in fact, quantum mechanics is "an embarrassment", the biggest one in science!) and some bullšit has to be worked on instead of quantum mechanics – and the political correctness makes it "mandatory" for everyone to respect such things once they're said, just like everyone is obliged to respect Allah and the whole garbage built around this ludicrous medieval idea just because some savages scream "Allahu Akbar" and murder a few Europeans.

I, for one, will never surrender to this political correctness. It's essential for the inner workings of physics to understand and explain why these efforts to sling mud at quantum mechanics result from the idiocy of the likes of Sean Carroll and why this flawed thinking and its champions belong to the intellectual dumping ground. These insights are at least as essential as the insights that have been labeled "positive" by the political correctness.

In science in general and physics in particular, it simply isn't true that statements must be respected as "respectable forever" once some people have made it. The scientific method is really built around the opposite principle, the elimination of the statements and hypotheses that have been shown to disagree with the observations. In other words, the whole scientific method is created out of the "negative" statements – out of the politically incorrect ones, if you wish. And all the "classical models" and "alternative interpretations" undoubtedly belong to the class of statements that have been refuted by the progress in physics and these refutations really represent a major part of the value that the mankind's knowledge of physics has accumulated.